For patients with stable coronary artery disease (CAD), percutaneous coronary intervention (PCI) may improve symptoms, but only in uncommon and specific clinical scenarios has it been shown to reduce mortality. Having PCI involves both risk and inconvenience, and thus it represents a classic preference- sensitive situation, in which treatment decisions should be aligned with the patient's values and preferences. There is evidence that current practice does not live up to this ideal. Surveys show that patients often misstate the benefits and risks of PCI and sometimes believe it cures their CAD and eliminates the need to control risk factors. Shared decision-making trials show that, once patients understand the role of PCI better, they choose it about 17% less often than in current practice. Furthermore, billing data show vast regional variation in PCI use; other studies have found that 12% of PCIs are inappropriate and 38% are of uncertain appropriateness. Our long-term goal is to determine what causes such variation in care and identify ways of making the decision-making process more patient-centered. There is currently is no questionnaire short enough for routine use that can measure how PCI decisions are made - i.e., how knowledgeable patients are about PCI, how involved they are they, and what their preferences are. Without such a questionnaire, we cannot tell whether the observed variation and inappropriateness are driven by patient misunderstanding of PCI, by variation in physicians' approaches to educating and involving patients during decision-making, or something else. Once the problem is identified, the fix will be very important for three reasons. First, patients wll be more likely to get PCI only if they understand and want it. Second, since the US spends $20 billion per year on PCI, even a 17% reduction in its use would save billions without increasing mortality. Third, if patients' understanding of the short-term nature of PCI benefits improves thei willingness to adhere to risk factor modification after PCI, outcomes could improve. In this project we will develop the first comprehensive, patient-reported measure of decisional quality for CAD that is feasible to implement in a variety of settings. We will accomplish this by: 1) Identifying the key elements to capture decisional quality and identifying candidate questions to address these elements, using patient and expert feedback (Aim 1); 2) Pilot testing a preliminary instrument in a diverse patient population to assess measurement properties and select a reduced set of candidate questions for further testing (Aim 2); and 3) Establish the reliability and validity of a new comprehensive decisional quality measure for single and repeated examinations (Aim 3). This will result in a multidimensional decisional quality instrument for patients with CAD that will be ready for implementation into routine care.